The Teleprompter

June 8, 2011

Invention is a difficult thing in this high-tech world of mobile computing devices. The invention process typically involves a huge and highly educated team of employees who are armed with rooms full of very expensive equipment.

This was also the age of the teleprompter, a mechanical-optical device that mitigated a major problem of early television - the lack of video recorders. Those were the days of incessant soap operas that have been replaced today by incessant talk shows. Everything was done live, and since such teleplays were done daily, rehearsals were short and occasionally ineffective. Actors and actresses would sometimes miss lines, and a scene was often saved only by an extemporaneous monologue by another actor.[2]

A teleprompter solves the memorization problem by presenting the script on a viewing pane directly in front of the camera. The mechanical teleprompter was patented by Jess Oppenheimer, who was the producer of the "I Love Lucy" television series.[3] Although the series was filmed, and the actors memorized their lines, it was still difficult for Lucille Ball to memorize commercials that she presented on-camera. The figure below shows the basic arrangement of Oppenheimer's teleprompter.

The optical element (23) is a partially-silvered mirror that allows the camera lens a reasonably clear optical path to the performer. This mirror also reflects a projected image of the script that's penned on a transparent sheet of plastic not unlike photographic film stock without an emulsion. An arrangement of lenses ensures that the script image is properly displayed as it "crawls" from the bottom of the screen to the top.

Oppenheimer's patent was filed on October 14, 1954, but the company most often associated with this concept, TelePrompTer, was founded at about the same time. The term, teleprompter, which describes the many variations of this concept, has become a generic term. TelePrompTer was founded by Fred Barton Jr., Irving Berlin Kahn and Hubert J. Schlafly. Schlafly, who invented variations of the teleprompter concept, along with other television-related inventions, including some for satellite communications, died on April 20, 2011, at age 91.[4-7] Schlafly, who eventually became the president of TelePrompTer, accepted an Emmy Award for the company in 1999.[4]

As technology evolved, so did the teleprompter. The most significant improvement was replacement of the script on transparency stock by a computer display. Eventually, teleprompter systems became a staple on podiums everywhere, where they made public speaking more oratorical and conversational. A teleprompter was used by former US President Herbert Hoover at the 1952 Republican Partynational convention.[4] Unfortunately, Hoover departed from the script in the middle of his speech, and there was some confusion before the teleprompter rolled again.[5]

Ubiquitous computing and inexpensive displays have allowed teleprompting to be incorporated into smaller public speaking sessions, such as church sermons. I'm still waiting for the science fiction version, a teleprompter in a pair or eyeglasses or a retinal display. It would help me remember the names of wives and children when I unexpectedly meet my former co-workers at the supermarket.

Why would the author of a blog that publishes articles about graphene, thermodynamics and quantum mechanics be interested in something as mundane as the teleprompter? The partially-silvered mirror is one of the most useful optical components. I worked on a team that developed a unique sensor that fired a light beam into free space and looked at the scattered light from the same direction. The optical circuit was exactly the same as the teleprompter, with a light-emitting diode replacing the projector, and a phototransistor replacing the camera. What's past is prologue.